Conventionally, a wiper apparatus for wiping off substances attached on a windshield to secure a visual field of a driver is mounted on a vehicle. The wiper apparatus is configured to convert a rotation movement of an armature of a wiper motor into a swing movement of a wiper arm. As a type of a mechanism for converting the rotation movement of the armature of the wiper motor into the swing movement of the wiper arm, a direct drive (DD) type and a link type has been known. First, a direct drive type wiper apparatus is provided with: a worm formed on the armature; and a worm wheel meshing with the worm, one end of the wiper arm is directly fixed to a rotation shaft serving as a rotation center of the worm wheel. In this direct drive type, the rotation movement of the armature is converted into the rotation movement of the worm wheel, and the swing movement of the wiper arm about the rotation shaft is performed. That is, the rotation shaft also serves as a pivot shaft of the wiper arm at the same time. One example of the direct drive type wiper apparatus is described in U.S. Patent Application Publication No. 2006/0053577.
On the other hand, a link type wiper apparatus is provided with: a worm formed on the armature; a worm wheel meshing with the worm; a pivot shaft serving as a swing center of the wiper arm; and a link converting the rotation movement of the worm wheel into the swing movement of the wiper arm. One example of the link type wiper apparatus is described in Japanese Patent Application Publication No. 2009-113569 and Japanese Patent Application Publication No. 2009-513442.
Of these wiper apparatuses, the wiper apparatus described in Japanese Patent Application Publication No. 2009-113569 is provided with: a wiper motor which is rotated normally and reversely within a predetermined angle range; an output shaft which the rotation movement of the wiper motor is transmitted to; a motor link which is swung integrally with the output shaft; a link rod coupled to the motor link via a ball joint; a pivot shaft serving as a swing center of the wiper arm; and a pivot link which is swung integrally with the pivot shaft and coupled to the link rod via a ball joint. An object of the wiper apparatus described in Japanese Patent Application Publication No. 2009-113569 is to reduce a space in an engine room, in which the wiper apparatus is installed. Japanese Patent Application Publication No. 2009-113569 discloses that the wiper motor is provided within a projection range of the windshield in a vehicle interior. Incidentally, Japanese Patent Application Publication No. 2009-513442 does not disclose a wiper motor for generating a drive power for swinging the wiper arm.